200,000 litres of oil leaked into waters off the coast of Brisbane from the Pacific Adventurer when their fuel tanks were damaged in rough seas on Wednesday. The figure is about ten times higher than the original estimate of twenty thousand litres of oil. The devastating diesel oil spill has spread along 60 kilometres (37 miles) of the Queensland coast. In addition, 31 containers with 620 tonnes of ammonium nitrate fertiliser flew overboard during the violent storm.

Questions are being asked why the Hong Kong cargo ship was out in seas with nine meter waves caused by Cyclone Hamish, a Category 5 tropical cyclone, as well as why the fertiliser containers were not properly secured. One of the overboard containers ruptured the hull of the Pacific Adventurer, causing between 30 to 100 tonnes of oil to spew from the severely damaged ship.

If the ammonium nitrate mixes with the heavy oil, an explosion could occur. None of the containers have been recovered. Some of these may float, but it is believed that they may have sunk which then may cause algal blooms.

The vessel’s owner, Swire Shipping, reported that a second leak began on Friday, when the ship began listing after docking at Hamilton for repairs. “As full soundings of the vessel’s tanks were being taken at the port to determine how much oil had leaked from the vessel, a small quantity of fuel oil escaped from the Pacific Adventurer,” it stated. The ship was brought upright, and a recovery vessel was used to suck up the oil from the water. The leak produced a 500m-long oil slick down the Brisbane River. Booms were placed around this oil spill so that a skimmer could clean up the second spill.

Swire Shipping could face clean up costs of AU$100,000 a day as well as fines up to AU$1.5million (US$977,000; £703,000) if found guilty of environmental breaches or negligence.

Sunshine Coast beaches are slowly starting to be reopened. The beach of Mooloolaba was still closed following reports of burning sensations from swimmers. 12 beaches remain closed; however, 13 have been reopened.

Over 300 state government and council workers are using buckets, rakes and spades in the clean up effort. Sunshine Coast Mayor Bob Abbott says the majority will be gone by Sunday afternoon. The full environmental impact on wildlife is not yet known. One turtle and seven pelicans have been found covered in oil.

There are concerns that the drinking water of Moreton Island is at risk, as the island uses water from the underground water table near the oil spill site.

“Every bucketload of contaminated sand has to be removed from the island by barge, and each bucketload from a front-end loader weighs about one tonne. It’s just an impossible task,” said Mr Trevor Hassard of the Tangalooma Dolphin Education Centre.

The commercial fishing industry has suffered from the incident. Trawlers won’t resume operations until Sunday evening, and any catches will be tested for human consumption.